Kate O'Sullivan is a British actress, singer, voiceover artist and impressionist.
A graduate of Drama Centre London now Central Saint Martins, she was taught by Yat Malmgren and Christopher Fettes.
Her first job after leaving Drama Centre was in the West End playing Cecily Cardew in The Importance of Being Earnest at the Whitehall Theatre (now Trafalgar Studios) with Hinge and Bracket. She played Magenta, the extra terrestrial French maid, in the 1991 revival of Richard O’Brien's The Rocky Horror Show starring Anthony Head and Craig Ferguson at the Piccadilly Theatre and Bristol Hippodrome Theatre. Other musicals include Lust with Denis Lawson at the Theatre Royal, Haymarket, and Bob Carlton’s Keep On Running at Birmingham Rep in which she played the lead Kathleen Karman. In 1994 O'Sullivan appeared with Eric Sykes in a nationwide tour of Ray Cooney’s farce Run For Your Wife. In 2008, O'Sullivan returned to the role of Barbara or “Lofty” in Run For Your Wife in a UK tour celebrating the play's 25th Anniversary.
Kate O'Sullivan featured as a writer/performer in Let The People Decide with Barry from Watford (Edinburgh Fringe, 2010). During the 2011 Edinburgh Fringe she performed sketches and stand-up with Sketch Department at The Merchant's Hall, Hannover St. In 2011 she appeared in Q&A: a showcase for new material & improvisation with Steve Furst and Lewis MacLeod at the Leicester Square Theatre.